2.5% off of everything sounds good on paper (although it is actually 2.13% as 2.5% will no longer be added to the price before tax rather than deducted from the price with tax), however the replacemnet on fuel of the reclaimable VAT with non-reclaimable duty means that haulage firms will actually end up paying more for their fuel which leads to price rises.
I also feel that very few retailers will even bother with the deduction as it is so minimal - can you see your newsagent, for example, knocking 2p off of a packet of Haribo? What about your council car park - will it now be 98p to park rather than £1? Will tickets for football be 50p less? Will it be £4.80 to the cinema instead of a fiver?
It just isn't going to happen.
The only ones to benefit will actually be the retailers who might make a small amount of additional profit. The public will only benefit if they are buying cars or aother high value goods.
The fact that the cut isn't until Monday will also kill off all shopping this weekend.